Wooden Buildings Can Safely Reach for the Sky

Last month Jim Anderton (MP for Wigram and Leader of the Progressive Party) spoke out about the opportunity for wood to provide a safe, ecologically sound and cost-effective building material to rebuild Christchurch city, see "The Press".

In a press release Mr Anderton pointed out that "It [wood] is a renewable, low-energy resource, there is a plentiful, sustainably-grown supply in New Zealand, modern timber construction produces little waste and the manufacture of building materials from wood is now generally non-polluting. Additionally, the increased use of wood would provide national benefits in the long term, including reduced fossil fuel consumption and CO2 emissions, an increase in the pool of retained carbon in wood and wood products, and the potential for the replacement of fossil fuel by burning wood waste materials."

Due to its high strength, low weight and flexibility researchers and designers are understanding that wood is an excellent option for construction of multi-level structures. In conjunction with engineered wood products such as laminated veneer lumber (LVL), oriented strand lumber and plywood, and new jointing and fastening systems, wood is providing excellent options for earthquake resistant single and multi-level construction.

Large wooden beams also have excellent fire ratings due to the process of slow surface charring protecting the inner sections of the beam allowing it to maintain its structural strength. Mr Anderton elaborated: "Supporting this is the fact that, in 1992, the New Zealand Building Code was amended to allow timber buildings of unlimited height, subject to meeting some performance requirements, whereas before that, three storeys was the maximum height for wooden buildings. Fire safety was one of the influential factors in the change."

Interest in multi-storey wooden buildings is also increasing in other parts of the world.

The Age has reported that the Grollo family plans to build Australia's first high-rise building from timber, at the old Carlton & United Breweries site in Swanston Street, Melbourne. The AU$100 million building will be made from soft-wood panels imported from Europe and fitted together in weeks to make 50 apartments over 10 storeys.

A study funded by the B.C. government to help promote the province's forestry sector will conclude that buildings as tall as 30 storeys could be made almost entirely out of wood, says Michael Green, an award-winning Vancouver architect leading the research. He has a vision for to reinventing the high-rise construction industry with wood challenging steel and concrete as the ideal building material.

"The exciting thing is, from an engineering point of view, we think we have something that is on track to be able to design -comfortably- 20 storey buildings," said Green. "And certainly, we believe, quite reasonably, we'll be able to stretch that to 30 storeys."

A nine-storey building in Britain now the world's tallest wooden structure. Green said a 10-storey project in Australia (see above), a 17-storey building in Norway and a 30-storey structure in Austria have been proposed recently.